1. Field of the Invention
The present invention relates to inflatable curtain airbags. More specifically, the present invention relates to a novel inflatable curtain airbag having one or more pleats that may be installed on or proximate to a vehicle's side roof rail.
2. Description of Related Art
Inflatable airbags enjoy widespread acceptance as passive passenger restraints for use in motor vehicles. This acceptance has come as airbags have built a reputation of preventing death and injury over years of use. Studies show that in some instances, the use of frontally-placed vehicular airbags can reduce the number of fatalities in head-on collisions by 25% among drivers using seat belts and by more than 30% among unbelted drivers. Other statistics suggest that in a frontal collision, the combination of a seat belt and an airbag can reduce the incidence of serious chest injuries by 65% and the incidence of serious head injuries by up to 75%. These numbers and the thousands of prevented injuries they represent demonstrate the life-saving potential of airbags and the need to encourage their use, production, and development.
Airbags are generally linked to a control system within the vehicle that triggers their initiation when a collision occurs. Generally, an accelerometer within the vehicle measures the abnormal deceleration caused by the collision event and triggers the ignition of an airbag inflator. This control system is often referred to as an electronic control unit (or “ECU”). The ECU includes a sensor that continuously monitors the acceleration and deceleration of the vehicle and sends this information to a processor that uses an algorithm to determine whether a deceleration experienced by the vehicle is a caused by a collision or accident. Additional sensors may be linked to the ECU to allow the proper detection of side-impact collisions, rollovers, etc.
When the processor of the ECU determines, based on a set of pre-determined criteria, that the vehicle is experiencing a collision, the ECU transmits an electrical current to an initiator assembly connected to an inflator that is coupled to the airbag module. The initiator activates the inflator. An inflator is a gas generator that typically uses a compressed or liquefied gas or mixture of gases, a solid fuel, or some combination of the above to rapidly generate a volume of inflation gas. The gas inflates the airbag, which deploys into the path of the vehicle occupant and absorbs the impact of the vehicle occupant.
Recently, airbag technology has continued to advance such that inflatable curtain airbags are now enlisted to provide roll-over protection as well as side impact protection. During a roll-over accident, the vehicle occupants can be jostled considerably, thereby causing the occupant to impact various parts of the vehicle interior. Even worse, the occupant may be ejected from the vehicle. Alternatively, a head or limb of an occupant may extend outside the vehicle during the roll-over. Such “occupant excursion” during roll-over accidents is a common cause of automotive fatality, particularly in the case of vehicle occupants that are not wearing a seat belt during the roll-over.
Conventional curtain airbags attempt to combat the dangers of side impact or roll-over accidents by having a curtain airbag unroll or unfold downward from the roof of the vehicle and then inflate beside the person as a means of preventing the person from hitting the door, window, or lateral side of the vehicle. Since a vehicle occupant may be leaning forward, reclined in the seat, or at any position in between, such curtain airbags are usually designed to be long enough to cover the whole interior side of the vehicle, protecting occupants in both front and rear passenger compartments.
Generally, the inflatable curtain airbag must be sized to hold large volumes of inflation gas and to descend below the window sill. Consequently, when not inflated the curtain airbag includes a significant amount of material. This material is then rolled, folded, or otherwise gathered to form a tight, tubular bundle. A wrapper (sometimes called a “sock”) that fits around the curtain is then added to ensure that the curtain airbag is kept rolled or folded.
The curtain is stored and mounted either on or proximate a roof rail of the vehicle. Such mounting is generally accomplished via a two-step process. First, the curtain must be held in the proper position. This can be done by either having multiple workers hold the airbag or by attaching the airbag to sophisticated jigs, hooks, or mounting brackets (collectively “brackets”) that have been placed into slots in the body of the vehicle. Once the curtain airbag has been secured in the proper location, the workers are free to affix the curtain airbag assembly to the vehicle using fasteners such as bolts, screws, rivets, and the like. Usually these fasteners are threaded into one or more attachment tabs that have been added along the top of the curtain airbag to facilitate the assembly and mounting process.
While currently known inflatable curtain systems have provided a significant improvement in the art, problems and drawbacks still exist that limit the ability of vehicle and airbag manufacturers to implement and use inflatable curtains on all motor vehicles. For example, many curtain airbags are designed such that as curtain deploys into the inflated configuration, the curtain will impact and/or be impeded by the vehicle's structure, trim panel, wiring, and/or other vehicle components. Such impact during deployment is extremely detrimental in that it increases the deployment time and/or prevents the curtain from becoming situated in an undesired position. As a result, the ability and effectiveness of the inflatable curtain to adequately protect a vehicle occupant during a crash is greatly reduced.
In order to avoid the problems associated with the curtain impacting the vehicle during deployment, vehicle and airbag manufacturers often add features such as pillar ramps, shape maintainers, folds, wrappers, or trim pieces (collectively “ramps”) are added to the inflatable curtain assembly. The ramps are designed to change the deployment trajectory of the inflatable curtain. As used herein, “deployment trajectory” is the path, course, or angle undertaken by the inflatable curtain as it is inflated and deployed within the vehicle. Preferably, the ramps change the deployment trajectory of the inflatable curtain such that the deployment of the curtain is not impacted or impeded by the trim panel or other interior portions of the vehicle.
Unfortunately however, the use of such ramps can significantly increase the total costs associated with producing, assembling, and installing the inflatable curtain airbag system for airbag manufacturers. Ramps increase the total number components required to produce the inflatable curtain system. As a result, airbag manufacturers are forced to expend additional resources to produce, design, and/or install the inflatable curtain. Perhaps more importantly, known ramps are often small components that are difficult to handle and use, and as such, airbag installers must expend additional seconds and/or minutes in order to properly position and install the ramps. As manufacturers incur costs for every moment that passes during the assembly process, even an increase of a few seconds or minutes in the assembly time represents a significant impact on the manufacturer's total production costs and overall profit margin of a mass-produced vehicle.
Moreover, the addition of ramps to the inflatable curtain system is undesirable in that the ramps will occupy valuable space proximate to the roof rail. Besides the inflatable curtain, various other vehicle components need to be installed proximate to the roof rail. Examples of such components include hand grips, lighting fixtures, sun or moon roof brackets, drain tubes, wiring, and heating and ventilation (HVAC) controls and ducts. In smaller or compact vehicles where space is at a premium, the addition of the ramps to the inflatable curtain system may take up and/or interfere with the space necessary to properly install these other vehicle components.
Accordingly, there is a need in the art for a novel inflatable curtain that addresses and/or solves one or more of the above-listed problems. Such a device is disclosed herein.